4.6
(32)
696
riders
45
rides
Gravel biking in Marin County offers diverse terrain across its varied landscapes, from rugged coastlines and redwood forests to lush valleys and open grasslands. The region is characterized by significant elevation changes, extensive fire roads, and single-track paths, providing a dynamic backdrop for exploration. Mount Tamalpais and the Marin Headlands feature prominently, offering panoramic views and a mix of challenging climbs and rewarding descents. This area is well-suited for no traffic gravel bike trails, allowing riders to experience natural beauty away from vehicular routes.
Last updated: July 7, 2026
4.8
(6)
73
riders
47.4km
04:21
1,270m
1,270m
Hard gravel ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels.
4.0
(2)
36
riders
65.9km
04:42
1,010m
1,010m
The Alpine Dam – Alpine Lake loop from Sleepy Hollow is a crown jewel among Marin County gravel biking routes, offering an incredible journey through varied landscapes. You'll wind through dense redwood forests, past the tranquil Alpine Lake, and experience the challenging yet rewarding terrain of the Mt. Tam Watershed. Keep an eye out for stunning viewpoints of Mount Tamalpais and even the Pacific Ocean from sections like the "Seven Sisters" on this 40.9-mile (65.9 km) adventure with 3311 feet (1009 metres) of climbing.
This difficult gravel biking route typically takes around 4 hours and 41 minutes, demanding very good fitness and advanced riding skills. For the best experience, it's generally recommended to tackle the loop in a counter-clockwise direction. Be ready for a mix of paved and unpaved surfaces, including challenging climbs and technical descents, and know that some sections might require you to dismount and push your bike.
What makes this one of the most popular gravel routes in Marin County is its combination of demanding terrain and consistently lauded scenery. Beyond the lake and dam, the region boasts diverse landscapes with oak-bay woodlands, savannas, grasslands, and forested hills, all contributing to its visual appeal. You'll also pass through charming Marin County towns, adding to the local flavor of this epic ride.

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5.0
(2)
28
riders
45.1km
03:18
770m
770m
Hard gravel ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels.
4.5
(2)
13
riders
27.8km
02:53
890m
890m
Hard gravel ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels.
15
riders
45.7km
03:59
1,180m
1,180m
The Phoenix Lake – Fish Gulch trail junction loop from Mill Valley offers a demanding yet incredibly scenic gravel biking adventure. You'll wind through diverse landscapes, from the cool shade of redwood forests to sun-drenched oak woodlands and open grasslands, with the promise of sweeping views of the Pacific Ocean and Golden Gate Bridge from higher points near Mount Tamalpais. This route is a true test of endurance, featuring steep and loose sections that demand very good fitness and bike handling skills.
Planning your ride requires a bit of foresight; while much of the loop is prime for gravel biking, be aware that the immediate trails around Phoenix Lake itself may not allow bikes. Parking is generally available in Mill Valley, but it's always wise to arrive early, especially on weekends, to secure a spot. Given the route's length and elevation, pack ample water and snacks, and consider starting early to make the most of the daylight.
This loop is a standout in the Mill Valley area, celebrated by local gravel bikers for its challenging terrain and the opportunity to combine dirt climbs with rewarding road descents. It showcases the region's extensive trail network and significant elevation gains, making it a prime destination for those looking to push their limits and experience the natural beauty of Marin County.
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Batterij Townsley is a place where nature and history meet. As you climb along the rugged cliffs of the Marin Headlands, the old coastal defense slowly emerges from the landscape. Once at the top, a panorama opens up that will leave you speechless: the Pacific Ocean, the Golden Gate Bridge, and the endless horizon. The abandoned bunkers and tunnels give the place a mysterious atmosphere, as if time has stood still here. A perfect stop to enjoy, wander, and completely immerse yourself in the view.
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Part of the coastal defenses along Coastal Trail, latest remnants here date from the WW II and early cold war era.
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Constructed in 1917 this dam forms Alpine Lake, which sites between Kent and Bon Tempe Lakes. The road across the top of the dam make it a great place to ride on a loop around the lake.
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This lake was formed by the building of Alpine Dam in 1917. It sits between Kent Lake and Bon Tempe Lake, and is popular for a variety of outdoor activities.
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Steep heading West can have traffic on SFD
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This large group picnic area is a lovely spot under a shady grove of towering redwoods that sits along Lagunitas Creek. There is piped drinking water and restrooms nearby, and if it is not in use, it is an excellent place to stop for lunch. If you are bike touring with friends and wish to spend time here, you can reserve this spot through the Samuel Taylor State Parks' department website.
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Marin County offers a fantastic selection of traffic-free gravel bike trails. You'll find over 40 routes specifically curated for a car-free experience, ranging from moderate to difficult, allowing you to explore the region's stunning landscapes without vehicle interference.
The traffic-free gravel trails in Marin County offer a diverse range of terrain. You'll encounter extensive fire roads, which are perfect for gravel biking, as well as some single-track paths. These routes wind through redwood groves, open grasslands, and along the rugged coastline, providing varied surfaces and breathtaking scenery.
While many of Marin County's gravel trails are rated moderate to difficult, there are options for beginners. Look for routes with less elevation gain and smoother surfaces. The region's extensive network of fire roads often provides more accessible paths for those new to gravel biking, allowing you to enjoy the natural beauty at a comfortable pace.
Yes, Marin County offers several car-free paths suitable for families. While specific gravel routes might be challenging for very young riders, many fire roads and designated bike paths provide safe and enjoyable experiences. Consider areas with flatter sections and scenic views, ensuring a pleasant outing for all ages.
For experienced gravel bikers seeking a challenge, Marin County delivers. Routes like the Old Mine Trail (lower) 🌲 loop from Mill Valley and the Fern Creek and spring loop from Mill Valley offer significant elevation changes and technical sections. The Mount Tamalpais area, with its challenging climbs and rewarding descents, is also a prime spot for advanced riders.
Absolutely! Many of the best traffic-free gravel bike experiences in Marin County are designed as loops, allowing you to start and end at the same point. Examples include the Fern Creek and spring – Pantoll Road loop from Mill Valley and the Alpine Dam – Alpine Lake loop from Sleepy Hollow, which offer diverse scenery and a complete riding experience.
Marin County's traffic-free gravel routes are renowned for their stunning vistas and natural attractions. You can expect panoramic views of the Pacific Ocean, the San Francisco skyline, and the Bay Area from spots like Mount Tamalpais. Trails often lead through majestic redwood groves, past serene lakes like Stafford Lake Park, and offer glimpses of unique geology. Don't miss the chance to visit the Marin Museum of Bicycling for a dose of local history.
Marin County offers excellent gravel biking conditions year-round, but spring and fall are particularly pleasant with mild temperatures and vibrant landscapes. Winter can also be a great time, especially after rain, as the trails are less dusty and the greenery is lush. Always check local weather conditions before heading out.
Yes, you'll find various amenities near many trailheads and in the charming towns of Marin County. For instance, you could grab a coffee or a bite at places like Splitrock Tap & Wheel, which is conveniently located. Many routes start or pass through towns like Mill Valley or Fairfax, offering plenty of options for refreshments.
The komoot community highly rates gravel biking in Marin County, with an average score of 4.6 stars. Reviewers consistently praise the region's unparalleled natural beauty, the extensive network of well-maintained fire roads, and the feeling of escaping into nature on car-free paths. The diverse terrain and stunning views, from redwood forests to coastal vistas, are frequently highlighted as major draws.
Beyond the general scenery, keep an eye out for specific highlights. You might encounter the challenging Flowy downhill section above Laguna Creek or the iconic Eldridge Grade Fire Rd Trail (upper half) 🚵 Mt Tam. For panoramic views, head towards Mount Tamalpais — East Peak or Cardiac Hill (Dipsea Trail, Mount Tamalpais State Park).
While many trails are best accessed by car, some areas in Marin County do offer public transport connections, particularly to towns like Mill Valley or Fairfax, from which you can often cycle to trailheads. For detailed information on public transport options and routes, it's advisable to check local transit schedules and bike-friendly policies.


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